OAA Mathematics 3 — Questions and Answers
Question 1: If the pattern is 2, 6, 18, 54, … what is the next number?
- 108
- 162 (Correct answer)
- 81
- 72
Correct answer: 162
Each term is multiplied by 3, so 54 × 3 = 162.
Question 2: A triangle has angles measuring 45°, 90°, and x°. What is x?
- 35°
- 55°
- 45° (Correct answer)
- 60°
Correct answer: 45°
The angles of a triangle sum to 180°, so x = 180 – 45 – 90 = 45°.
Question 3: What is 15% of 200?
- 25
- 30 (Correct answer)
- 35
- 20
Correct answer: 30
15% of 200 = 0.15 × 200 = 30.
Question 4: Solve for n: 4n – 7 = 17
- n = 4
- n = 5
- n = 6 (Correct answer)
- n = 3
Correct answer: n = 6
4n = 17 + 7 = 24, so n = 24 ÷ 4 = 6.
Question 5: A cylinder has a radius of 3 cm and a height of 10 cm. What is its volume? (Use π ≈ 3.14)
- 94.2 cm³
- 282.6 cm³ (Correct answer)
- 188.4 cm³
- 565.2 cm³
Correct answer: 282.6 cm³
V = πr²h = 3.14 × 9 × 10 = 282.6 cm³.
Question 6: Which expression represents 'seven less than twice a number n'?
- 7 – 2n
- 2n – 7 (Correct answer)
- 2(n – 7)
- 7 – n/2
Correct answer: 2n – 7
'Twice a number n' is 2n, and 'seven less than' means subtract 7, giving 2n – 7.
Question 7: The table shows test scores: 78, 85, 92, 85, 70, 85, 90. What is the mode?
- 85 (Correct answer)
- 83.6
- 90
- 78
Correct answer: 85
The mode is the value that appears most often; 85 appears three times.
OAA Mathematics 3
If the pattern is 2, 6, 18, 54, … what is the next number?